Distillation means, including solar distillation means, for distillation of, say, ocean water are well known as shown in U.S. Pat. Nos. 3,257,291; 3,317,406; 3,775,257; 4,046,639; 4,110,172; 4,118,283, and numerous other patents. None, however, make use of a vacuum tank, or container, for the liquid, and a discharge tube containing a liquid column supported by atmospheric pressure extending downwardly from the tank for maintaining a subatmospheric pressure within the vessel above the liquid surface.